The present invention relates to a continuous vibro fluidized bed roaster using flue gas, for roasting/toasting of cereals, pulses, spices, oil seeds and ready to-eat snack foods. The device of the present invention is particularly useful for roasting/toasting cereals, pulses, spices, oil seeds and ready to-eat snack foods which enhances the organoleptic properties. The product processed by using the roaster has uniform color, moisture and other sensorial properties, and the material is process ed under hygienic conditions in a continuous manner.
The patent search showed batch type roasters are patented in Federal Republic of Germany, patent No. DE 3116723 C2. There is only one report where vibratory mode was employed in fluidized bed roaster (Weyell, 1997) Patent No. 0039-4653. This unit from Vibro (Germany), was used for roasting hazelnuts, desiccated coconut etc. However, this unit happens to be a batch type unit.
Presently the roasters are of batch type, continuous sand roasters, rotary type roasters and air jet roasters. The major problems in these roasters are non uniform roasting, color, scorched and blackened particles, sand and ash entrapment after processing, which leads to poor quality product. These units are tedious in operation and the operator has to work under the direct influence of smoke and flame and sand roasters are not suitable for roasting of spices like chilies, coriander etc. In case a suitable device is made available for continuous roasting of cereals, pulses, spices, oil seeds and ready to-eat snack foods which would result in reduction in hardship, clean and hygienic end product free from sand and ash and will have uniform color of roasting etc. Realizing the importance and necessity, The Central Food Technological Research Institute, Mysore has successfully developed a device for roasting/toasting cereals, pulses, spices, oil seeds and ready to-eat snack foods.
Hitherto the process of roasting/toasting of cereals, pulses, spices, oil seeds and ready to-eat snack foods is done either in rotating units or conveyorised units. Rotary units have the standard ovens for roasting all types of flakes in break fast food industry. Flakes are difficult to roast in a fixed position on flat board leading to uneven product color. Where as rotary ovens suspend flakes in heated air which heats all surfaces evenly and results in uniform roasting and color. Rotary units consist of an insulated outer shell, with an inner-rotating cylinder. The inner shell is made up of plain carbon steel and the outer shell, is of mild steel and insulated suitably. Perforated inner shell is used for large flakes as corn, wheat, where as non-perforated cylinders is employed for handling small product. An important feature of rotary type roasting units is the presence of lifters inside the inner cylinders for uniform mixing of the product. Band roasters are used for large products of thickness 6-20 mm and for those that will crumble in the drum. These are quite simple units in which conveyor moves through the oven chamber and can be direct or indirect fired. A more efficient roaster is a jet zone unit, in which hot air is forced through the nozzle, which directs them as high velocity jets on to the product. This result in more uniform product than conveyor roasted products. But jet zone unit is not suitable for roasting of oil seeds, breakfast foods etc., as the air jet of high velocity and would damage the final shape of the product.
The drawbacks of using the above types of roasters are:
There is no uniformity in roasting.
Cereals, pulses, oil seeds, spices and breakfast foods cannot be roasted in a single device.
Roasting of unsorted material is not possible.
The roasted material will not have uniform color.
The product will have scorched/blackened particles.
The end product will be contaminated with sand and ash.
The operation is tedious and the operator has to work under the threat of flame and smoke.
Sand roasters are not suitable for spices like chilies, coriander etc.
The jet zone roaster would damage the products final shape and is not suitable for breakfast foods and spices like chilies.
Incase a device is made available for roasting/toasting cereals, pulses, spices, oil seeds and ready to-eat snack foods continuously, would result in reduction in human drudgery, clean and hygienic end product free from sand, ash and will have uniform color and uniform roasting.
The main object of the present invention is to provide a continuous vibro fluidized bed roaster for roasting/toasting of cereals, pulses, spices, oil seeds and ready to-eat snack foods continuously, using flue gas.
Another object is to roast the cereals, pulses, spices, oil seeds and ready-to-eat snack foods hygienically through mechanized operations, using the continuous vibro fluidized bed roaster using flue gas.
Still another object is to provide a device to produce roasted cereals, pulses, spices, oil seeds and ready-to-eat snack foods of uniform color, texture and other sensorial properties.
Still another object of the present invention is to reduce manual drudgery.
Yet another object is to increase productivity.
Still another object is to provide a device capable of working with a wide range of material to be roasted.